Disappearing feeder for metallurgical furnaces



Sept. 15, 1931. R. A. WAGSTAFF DISAPPEARING FEEDER FOR METALLURGICAL FURNACES Original Filed Oct.- 11 1927 I N V EN TOR. Richard AJ Vaesia ff BY, WW-M A TTORNEY atented Sept. 1 5, 1931 UNITED STATES PATENT OFFICE RICHARD A. WAGSTAFF, OF SALT LAKE GIT'LT, UTAH, ASSIGNOR TO AMERICAN SHELT- ING AND REFINING COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY DISAPTEABING FEEDER FOR METALLURGICAL FURNACES Application filed October 11, 1927, Serial No. 225,410. Renewed April 12, 1930.

The invention relates in general to metallurgy, and more particularly, to a method of and apparatus for feeding dusty fines to a reverberatory smelting furnace.

If very fine, dusty charges are fed to a reverberatory or'other smelting furnace and no special precautions are taken, the draft will blow large portions of the charge up the flue and on to the adjoining parts of the brick work. This results not only in a waste of material but also in damage to the furnace because the charge frequently attacks the brick work. Furthermore, this condition makes it difficult to properly distribute the charge over the bath. According to the invention these disadvantages are overcome. simply and expeditiously. A method of and apparatus for feeding fines to a reverberatory furnace is provided which not only eliminates the above disadvantages but also has additional advantages which will be apparent as the description proceeds.

The apparatus in general comprises a disappearing feeder including an extendible tube which can be projected through openings in the walls of the furnace above the bath line or surface of the bath. The tube may be projected into the furnace so that its lower end is slightly above the bath line and at an angle thereto. The dusty charge is introduced into the tube at a point outside the furnace and it slides by gravity down through the tube into the furnace. The velocity attained serves to distribute the dust over a considerable portion of the bath, there being a slight free fall and no piling of the charge under the tube. Any number of these tubes may be provided at different parts of the furnace in any position and through any wall, to give the desired distribution.

The invention also consists in certain new and original features of operation and cons'truction hereinafter set forth and claimed.

Although the novel features which are be lieved to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. 1 is an elevation partly in section of one form of apparatus for performing the method of the invention;

Fig. 2 is a diagrammatic top plan view of one type of reverberatory furnace show Referring now to the drawings the furnace denoted generally by 1 may be of any type of metallurgical furnace to which it is desired to feed dusty charges. A particular type of reverberatory furnace is shown, but it is understood that this is merely for purpose of illustration. This furnace comprises the usual side walls 2 and an archroof 3, the roof or walls having openings therein through which the disappearing feeder may be projected. The structural detail of the furnace is omitted for the sake of clarity. In Fig. l the arch roof 3 is shown provided with an opening 4:, the opening having a hollow ring providing a water jacket 5. The ring is provided with a gate 11 having a pivoted connection at the top thereof and adapted to swing inwardly and to gravitate to a closed position.

Above the furnace 1 is an upper level or floor 6 supported by suitable structural members and having a trackway 7 thereon. Between the rails of the trackway will be located a suitable hopper 8 having a depending pipe 9 ending in a lower discharge port 10.

Located in line with the charge opening 4 is the disappearing feeder. The disappearing feeder comprises two upper and two lower guide rails 13 and 14 suitably held in the position shown by structural members (not shown). Thefeed tube 15 has its lower end open and its upper end closed and is provided with upper and lower spaced clamping collars l6 and 17. To each collar is journalled a pair of flanged wheels 18, each flanged wheel running between its cooperating upper and lower guide rail 13 and 14. The tube 15 is provided with a port 19 in its upper side adapted to register with the port 10 when the tube is in its projected position as shown in Fi 1. Suitable flanges 20 and 21 are rovi ed to insure an air-tight connection between the ports 10 and 19.

The lower portion of the feed tube 15 is adapted to enter the furnace thru the charge opening 4, and is provided with a cooling jacket 22. A dividing wall 23 is provided in the jacket on opposite sides thereof and extending from the upper end almost to the lower end thereof to insure circulation of cooling medium down one side of the jacket and up the other side. Flexible connecting pipes 24 are provided for circulating the cooling medium which may be either air or water.

For operating the feed tube 15, which may be of considerable dimensions, an air cylinder 27 is provided, being suitably secured to the guide rails 14. A piston 28 is disposed in the air cylinder 27 and a piston rod 29 connects the piston with the lower collar 17. Inlet pipes 30 and 31 are provided at the ends of the cylinder 27 so that air may be admitted to draw the feed tube 15 out of the furnace, or to project it into the furnace, as is desired.

Normally the feed tube occupies a retracted position out of the furnace and the charge opening door or gate 11 is closed to prevent air leakage into the furnace. When it is desired to charge the furnace, the feed tube 15 is projected into the furnace, it automatically opening the door, to the position shown in Fig. 1, the lower end being disposed slightly above the surface of the bath 32. The ports 10 and 19 are in register and the dusty charge is dumped from a car (not shown) on the tracks 7 into the hopper 8, whence it drops by gravity into the furnace. The velocity attained by the charge is sufiicient to scatter the charge from the end of the pipe well over the bath in that particular part of the furnace, no piling directly beneath the pipe being allowed the charge substantially immediately entering the bath. Most of the fall of the charge through the moving furnace gases is eliminated, but a small free fall is permitted to cause the required scattering or distribution of the charge over the bath.

If desired, an auxiliary air line may be connected either to the depending pipe 9 or to the charge tube 15 so that any charge which happens to remain in the tube may be blown into the furnace.

It will be understood that the charge openings may be placed in any desirable position in the side wall, bridge wall, roof or arch of the furnace.

Thus it will be seen that a method and apparatus for charging a reverberatory furnace with fines has been provided, in which the charge can be introduced at any desirable point in the furnace and any esired distribution of the charge can be obtained. The undesired dusting or blowing of the dusty charge by the furnace gases is eliminated, this saving the dust which would ordinarily be wasted by being blown up the flue and also preventing the deposition of dust on the brick work, and the consequent reduction of the life of the furnace. Furthermore, the construction is such that the furnace arch is freed of all obstructions, this providing better radiation and permittin easier repairs. In addition, the method and apparatus is such that the operation is simple. No special care need be taken after the method and apparatus is once adjusted to working conditions. The apparatus and method may be utilized efficiently by workmen having no special skill. Furthermore, the apparatus is of rugged construction, and is not likely to get out of order and will give long and efficient service.

Although certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the several steps of the process and in its operation and in the form and details of the apparatus illustrated may be made by those skilled in the art without departing from the spirit of the invention.

IVhat is claimed is:

1. In combination, a furnace having a charge opening, a disappearing feeder device comprising a tube in line with said opening, said tube having a mouth, guide means to allow moving said tube into and out of said furnace, a stationary hopper having a port in register with said mouth whensaid tube is in said furnace, said mouth being movable transversely to said port.

2. In combination, a furnace having an opening, said opening having a self-closing gate opening inwardly, a disappearing feeder device comprisin a feed tube in inclined position in line with said opening, said tube having a mouth in its upper inclined wall, a guide track, wheels journalled on said tube rolling on saidtrack, means for moving pipe into and out of said furnace, a stationary hopper having a port in register with said mouth when said tube is in said furnace.

3. In combination, a reverberatory furnace having an opening in a wall above the bath line, said opening having a self-closing gate opening inwardly, a disappearing feeder dewice comprising a feed tube in inclined position in line with said opening, said tube having a mouth in its upper inclined wall, a guide track, wheels journalled on said tube to sai on said track, an air cylinder secured guide track having a piston attached to said pipe for moving pipe into and out of said furnace, a stationar hopper having a port in register with sai mouth when said rolling tube is in said furnace.

4. The method of feeding a reverberatory furnace with fine charges which comprises projecting a tube through the furnace shell to a position where the tube is inclined to the surface of the bath and the lower end thereof is close as possible above saidsurface, introducing said charges into said tube outside said furnace and allowing them to slide into the furnace by gravity and to gain sufficient velocity to scatter well, ina substantially uniform blanket, over the surface of the bath without contacting the side walls of the furnace,said charges being introduced in such quantity that they substantially immediately enter the bath, said charges having a small free fall in the furnace, said fall being below the main gas stream of the furnace.

5. The method of feeding a reverberatory furnace having a bath, with fine charges which comprises introducing said charges into the interior at a point as close as possible above the surface of the bath and below the main gas stream of the furnace with sufiicient velocity to cause the charges to spread well over the surface of the bath in a substantially uniform blanket and in such quantities that the charges substantially immediately enter the bath, without contacting the side walls of the furnace.

In testimony whereof I have hereunto set my hand. I

RICHARD A. WAGSTAFF. 

